After updating to 0.9.21, (I have also loaded 0.9.22) I started receiving this error every time I turn on my laser. As you can see, Jay from JTech Photonics, showed me how to create a Macro to clear error then all works fine. The question is why does this happen and to fix it?
I have an Acro 7W laser from Jtech. Running windows10. GRBL 1.1f